package com.itheima.marking_system.filter;

import com.alibaba.fastjson.JSON;

import com.itheima.marking_system.pojo.common.BaseContext;
import com.itheima.marking_system.pojo.common.R;
import com.itheima.marking_system.utils.jwt.JwtUtils;
import io.jsonwebtoken.Claims;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.util.AntPathMatcher;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerMapping;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已经完成登录
 */
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter{
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Value("${jwt.secret}")
    private String secret;
    @Value("${jwt.tokenName}")
    private String tokenName;
    @Value("${jwt.expiration}")
    private long expiration;


    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //判断当前拦截到的是Controller的方法还是其他资源
        Object handler = request.getAttribute(HandlerMapping.BEST_MATCHING_HANDLER_ATTRIBUTE);
        if (!(handler instanceof HandlerMethod)) {
            //当前拦截到的不是动态方法，直接放行
            filterChain.doFilter(request,response);
            return;
        }

//        //1、获取本次请求的URI
//        String requestURI = request.getRequestURI();// /backend/index.html
//
//        log.info("拦截到请求：{}",requestURI);
//
//        //定义不需要处理的请求路径
//        String[] urls = new String[]{
//                "/teacher/login",
//                "/teacher/logout",
//                "/teacher/register",
//        };
//
//
//        //2、判断本次请求是否需要处理
//        boolean check = check(urls, requestURI);
//
//        //3、如果不需要处理，则直接放行
//        if(check){
//            log.info("本次请求{}不需要处理",requestURI);
//            filterChain.doFilter(request,response);
//            return;
//        }
        //TODO:session登录
        //TODO:JWT登录
        String token = request.getHeader(tokenName);

        //4、如果需要处理，则检查用户是否登录
        //TODO:JWT解析
        try{
            Claims claims = JwtUtils.parseToken(token, secret);
            Long empId = (Long) claims.get("teacherId");
//            BaseContext.setCurrentId(empId);
            log.info("用户已登录，用户id为：{}",empId);
            filterChain.doFilter(request,response);
            return;
        }catch (Exception e){
            log.error("JWT解析失败：{}",e.getMessage());
            response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
            return;
        }

    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls,String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if(match){
                return true;
            }
        }
        return false;
    }
}
